diff --git a/Makefile b/Makefile
index 635993f..a6913fd 100644
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@
 # --- control global project settings
 # RELEASE=1 -> enable optimisation, then disable debug
 # RELEASE=0 -> disbale optimisation, then enable debug
-RELEASE=0
+RELEASE=1
 
 # --- project architecture
 # program name
diff --git a/docs/Graphs.ods b/docs/Graphs.ods
index 16918a1..ab7beed 100644
Binary files a/docs/Graphs.ods and b/docs/Graphs.ods differ
diff --git a/src/drivers/lcd.c b/src/drivers/lcd.c
index 0fcfffb..c784193 100644
--- a/src/drivers/lcd.c
+++ b/src/drivers/lcd.c
@@ -6,7 +6,11 @@ enum mode {
 	UNDEFINED
 };
 
-static int mode = UNDEFINED; 
+//TODO make the driver dynamic ?
+static TIM_TypeDef* timer = 0;
+static uint8_t mode = UNDEFINED; 
+static uint8_t rows = 0;
+static uint8_t columns = 0;
 
 //------------------------------------------------------------------------------
 // internal functions
@@ -39,18 +43,19 @@ int set_mode_write(void) {
 }
 
 void wait_for_ready(void) {
-	// configure the lcd
-	if(mode != READ) if(set_mode_read()) return;
-
-	// read D7 pin
-	for(;;) {
-		io_set(GPIOA, PIN_11);
-		for(int i=0; i<1000; ++i); //timer_wait is overkill here
-		if(!io_read(GPIOB, PIN_4)) break;
-		io_clear(GPIOA, PIN_11);
-		for(int i=0; i<1000; ++i); //same
-	}
-	io_clear(GPIOA, PIN_11);
+	//TODO debug that
+//	// configure the lcd
+//	if(mode != READ) if(set_mode_read()) return;
+//
+//	// read D7 pin
+//	for(;;) {
+//		io_set(GPIOA, PIN_11);
+//		for(int i=0; i<1000; ++i); //timer_wait is overkill here
+//		if(!io_read(GPIOB, PIN_4)) break;
+//		io_clear(GPIOA, PIN_11);
+//		for(int i=0; i<1000; ++i); //same
+//	}
+	timer_wait_ms(timer, 2, 0); //wait max delay
 }
 
 void write_byte(uint8_t byte) {
@@ -59,7 +64,7 @@ void write_byte(uint8_t byte) {
 
 	// start tranfert
 	io_set(GPIOA, PIN_11);
-	timer_wait_us(TIM1, 1, 0);
+	timer_wait_us(timer, 1, 0);
 	
 	// send the data
 	io_write(GPIOA, (byte >> 0) & 0x1, PIN_8);
@@ -76,8 +81,12 @@ void write_byte(uint8_t byte) {
 }
 
 //------------------------------------------------------------------------------
-// API functions
-int lcd_init(TIM_TypeDef* tim) {
+int lcd_init(TIM_TypeDef* tim, uint8_t col, uint8_t row) {
+
+	timer = tim;
+	columns = col;
+	rows = row;
+
 	// disable JTAG, as it utilise needed pins, SWD remains usable in 
 	// synchronous mode
 	RCC->APB2ENR |= 0x1;
@@ -91,17 +100,17 @@ int lcd_init(TIM_TypeDef* tim) {
 	if(set_mode_write()) return -1; //no check in case the pins were used 
 									//somewhere else
 
-	// select instrution register
+	// select instruction register
 	io_write(GPIOA, LCD_MODE_CMD, PIN_10);
 
 	// begin initialisation sequence
-	timer_wait_ms(tim, 15, 0);
+	timer_wait_ms(timer, 15, 0);
 	write_byte(LCD_FUNC_SET | LCD_FUNC_8BIT | LCD_FUNC_2LINE | 
 			LCD_FUNC_5x8DOTS);
-	timer_wait_ms(tim, 5, 0);
+	timer_wait_ms(timer, 5, 0);
 	write_byte(LCD_FUNC_SET | LCD_FUNC_8BIT | LCD_FUNC_2LINE | 
 			LCD_FUNC_5x8DOTS);
-	timer_wait_us(tim, 150, 0);
+	timer_wait_us(timer, 150, 0);
 	write_byte(LCD_FUNC_SET | LCD_FUNC_8BIT | LCD_FUNC_2LINE | 
 			LCD_FUNC_5x8DOTS);
 	wait_for_ready();
@@ -121,7 +130,39 @@ int lcd_init(TIM_TypeDef* tim) {
 			LCD_CTRL_BLINK_ON);
 	wait_for_ready();
 	write_byte(LCD_CLEAR);
-	wait_for_ready();
 
 	return 0;
 }
+
+void lcd_send_cmd(uint8_t cmd) {
+	// wait for the screen
+	wait_for_ready();
+
+	// select instruction register
+	io_write(GPIOA, LCD_MODE_CMD, PIN_10);	
+
+	// send the command
+	write_byte(cmd);
+}
+
+void lcd_print(const char* txt) {
+	// prepare data
+	const char* c = txt;
+	
+	// wait for the screen
+	wait_for_ready();
+
+	// select data register
+	io_write(GPIOA, LCD_MODE_DATA, PIN_10);
+
+	// send the caracters until end of string
+	while(*c != '\0') {
+		wait_for_ready();
+		write_byte(*c);
+		c++;
+	}
+}
+
+void lcd_set_cursor(uint8_t col, uint8_t row) {
+	lcd_send_cmd(LCD_DDRAM_ADDR | col);
+}
diff --git a/src/drivers/lcd.h b/src/drivers/lcd.h
index d7086be..5eba6e1 100644
--- a/src/drivers/lcd.h
+++ b/src/drivers/lcd.h
@@ -5,6 +5,7 @@
 #include "../config.h"
 #include "timer.h"
 #include "io.h"
+#include <stdlib.h>
 
 //------------------------------------------------------------------------------
 /* LCD mode selection */
@@ -17,7 +18,7 @@ enum lcd_register {
 /* LCD commands */
 enum lcd_command {
 	LCD_CLEAR			= 0x01,
-	LCD_CR				= 0x02,
+	LCD_CUR_HOME		= 0x02,
 	LCD_ENTRY			= 0x04,
 	LCD_DISP_CTRL		= 0x08,
 	LCD_SHIFT			= 0x10,
@@ -67,11 +68,24 @@ enum lcd_func_option {
 };
 
 //------------------------------------------------------------------------------
-int lcd_init(TIM_TypeDef* tim);
+/** lcd_init
+ * 	initialise the lcd, needed before anything else can be done
+ * 	the timer is used for delays and can't be in use when lcd functions are 
+ * 	called
+ */
+int lcd_init(TIM_TypeDef* tim, uint8_t col, uint8_t row);
 
-void lcd_write(uint8_t byte);
+/** lcd_send_cmd
+ * 	send the specified command to the lcd
+ */
+void lcd_send_cmd(uint8_t cmd);
 
-uint8_t lcd_read(void);
+/** lcd_print
+ *  print a null-terminated string on the lcd
+ */
+void lcd_print(const char* txt);
+
+void lcd_set_cursor(uint8_t col, uint8_t row);
 
 #endif
 
diff --git a/src/main.c b/src/main.c
index 5933cbb..6349e2c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,9 +1,9 @@
 #include "drivers/rcc.h"
 #include "drivers/io.h"
+#include "drivers/lcd.h"
 #include "drivers/adc.h"
 
 Clock_t sysclks;
-
 #include "drivers/timer.h"
 
 int val = 0;
@@ -12,6 +12,8 @@ uint16_t data = 0;
 static void timeout_cb(void) {
 	io_write(GPIOC, val, PIN_13);
 	val = !val;
+	data = adc_read(ADC1, 2);
+	data -= adc_read(ADC1, 3);
 }
 
 int main(void) {
@@ -22,16 +24,31 @@ int main(void) {
 		return 0;
 	io_write(GPIOC, 1, PIN_13);
 
-	timer_tick_init(TIM2, 1000, timeout_cb);
-	timer_start(TIM2);
-
-	if(io_configure(GPIOA, PIN_4 | PIN_5, IO_MODE_INPUT | IO_IN_ANALOG, 0))
+	if(io_configure(GPIOA, PIN_2 | PIN_3, IO_MODE_INPUT | IO_IN_ANALOG, 0))
 		return 0;
 	if(adc_init(ADC1)) return 0;
 
-	for(;;){
-		data = adc_read(ADC1, 5);
-		data -= adc_read(ADC1, 4);
+	//int test = 0;
+
+	timer_tick_init(TIM2, 1000, timeout_cb);
+	timer_start(TIM2);
+
+	lcd_init(TIM1);
+	lcd_print(" et paf");
+	lcd_print("Hello world!");
+	lcd_send_cmd(LCD_CUR_HOME);
+	lcd_send_cmd(LCD_CUR_HOME);
+	lcd_set_cursor(5, 1);
+
+
+	while(1){
+		lcd_print("loop");
+		lcd_print("loop2");
+		lcd_print("loop3");
+		lcd_print("loop4");
+		//voltage = data*4.0f/4095.0f;
+		//temp = (voltage-0.45)/0.04f;
+		timer_wait_ms(TIM1, 200, 0);
 	}
 
 	return 0;
diff --git a/src/target/STM32F103XB.ld b/src/target/STM32F103XB.ld
index 9d1604b..5c80b6a 100644
--- a/src/target/STM32F103XB.ld
+++ b/src/target/STM32F103XB.ld
@@ -6,8 +6,8 @@ STACK_SIZE = 0x400;
 
 MEMORY
 { 
-  FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 64K
-  RAM (rwx) : ORIGIN = 0x200000F0, LENGTH = 20K - (0xEC+0x4)
+  FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 32K
+  RAM (rwx) : ORIGIN = 0x200000F0, LENGTH = 10K - (0xEC+0x4)
 }
 
 /* Linker script to place sections and symbol values. Should be used together